"I don't think the ranged thing is a fundamental limit of magic, but it's certainly a practical one as far as the magic we know goes - if you want to affect something at range, you have to involve some kind of intermediary, and it's always a ritual rather than just a spell.
Realms are both places and - schools of magic, yes, although not split up anything like that word implies. More the kind of place that 'plane' implies, yes.
It's possible to create a regio, but it's a long term project consuming a lot of resources and I'm not convinced I know a sure-fire recipe, although I know some of the theory behind how it could work. It would probably depend how - close? - we are to the Realms of magic, whether it could work at all here. Generally it's much easier if you can get an Eternal's attention and sponsorship to the project, which is a bit of a chicken and egg situation if you don't have a single regio to begin with - although if your magic can't detect them, or doesn't distinguish them from noise, there might be plenty already that nobody has had the right tools to study?
Citadel Guard - or I think it's formally The Guard of the Citadel but nobody calls it that - not Citizen Guard. Uh, standard basic army training for a while, a lot of running and being shouted at and formations and all that. The ones who could run in full armour and still parry with a sword afterwards went on to front line training, steady hands to physick, those who were left and had a bit of ritual theory - like me - to the ritual auxiliary. It was a bit of a shock to the system at first, but nothing like actually being in a combat situation, and the ritual auxiliary training was a bit disappointing, to be honest; I think by that point they were worried we'd get bored and wander off back to a wizard-tower with their training, so they weren't inclined to push us any more.
I joined because it was the easiest way to get out of my parents' wizard-tower and not have to think too much about where to go next; not many Urizeni are very keen on a career that involves enforced physical activity or following orders, so the army is always recruiting."
He's almost succeeded at putting her at her ease, she's almost forgotten she's in a hostile environment at all; it appears 'magic' and 'herself' are some of her favourite conversational topics, and it's much easier just to indulge in them than to consider what might come next.